* Daniel P. Berrangé ([email protected]) wrote: > On Mon, Nov 25, 2019 at 06:50:21PM +0000, Dr. David Alan Gilbert wrote: > > Hi, > > There's been quite a bit of discussion about where virtiofsd, our > > implemenation of a virtiofs daemon, should live. I'd like to get > > this settled now, because I'd like to tidy it up for the next > > qemu cycle. > > > > For reference it's based on qemu's livhost-user+chunks of libfuse. > > It can't live in libfuse because we change enough of the library > > to break their ABI. It's C, and we've got ~100 patches - which > > we can split into about 3 chunks. > > > > Some suggestions so far: > > a) In contrib > > This is my current working assumption; the main objection is it's > > a bit big and pulls in a chunk of libfuse. > > My main objection to 'contrib/' is actually the perceived notions > about what the contrib directory is for. When I see 'contrib/' > code in either QEMU, or other open source projects, my general > impression is that this is largely unsupported code which is just > there as it might be interesting to someone, and doesn't typically > get much ongoing dev attention. > > Parts that are fully supported & actively developed by projects > usually live elsewhere like a src/ or lib/ or tools/ directory. > > This has kind of been the case with QEMU historically, with > the vhost-user-blk, vhost-user-scsi not being real production > quality implementations. Rather they are just technology demos > to show what you might do. vhost-user-gpu/input blurred this > boundary a bit as they're more supported tools, and so I'd > argue contrib/ probably wasn't the right place for them either > in hindsight. > > virtiofsd is definitely different as it is intended to be a > fully production quality supported tool with active dev into > the future IIUC. > > IOW, if we did decide we want it in QEMU, then instead of > '$GIT/contrib/virtiofsd', I'd prefer to see '$GIT/virtiofsd'.
I'm not sure it deserves a new top level for such a specific tool. > > b) In a submodule > > > > c) Just separate > > > > Your suggestions/ideas please. My preference is (a). > > What I'm wondering is just how much sharing / overlap of code and concepts > and community operation there is going otbetween QEMU and virtiofsd. From > the tech POV, IIUC, the main blocker it would need to be in QEMU is because > it links to libvhost-user and we've not declared that to be a stable API > for 3rd party linking. > > Personally I'm always biased towards self-contained apps being in their > own repositories, rather than bundling too much stuff into one repo. You > can see that in the way we've created independant git repos for any libvirt > module that didn't need to be part of the main libvirt.git. > > To me the key benefit this gives is flexibility in approach. ie the app > doesn't need to blindly follow every precedent that QEMU has set. It > can instead take the most appropriate path for its needs. For example... > > It could use meson for its build system already. This would be good as > builds will be done in a matter of seconds. For contributors it would > be a much less daunting project to join as it wouldn't be lost in the > firehose of other non-virtiofsd contributions on qemu-devel. > > It doesn't have to follow QEMU's 3-times a year release model, with 6 > week long freeze periods. It can be more agile releasing 6 times a year > with 1 week freezes if desired, I personally think tihs would be quite > desirable for a young project like virtiofsd which is evolving rapidly > as it would get new work available to users much more rapidly. Form virtiofsd's point of view I'm not that worried about the release cycle; Given that features have to go through virtio standardisation, the release ycle is unlikely to be a bottleneck. > It doesn't have to follow QEMU's API stability & deprecation policies. > It could be more flexible in taking non-compatible changes, which again > may be valuable for a young rapidly evolving app. > > > > Anyway to be clear, I'm not a contributor to virtiofsd, nor likely to > be one in the future, so just consider this a personal POV. From QEMU's > POV I don't think it'll matter whether virtiofsd in or out of QEMU git. > It is more about the impact & burden QEMU's dev process & standards might > impose on virtiofsd itself. As a qemu contributor, your opinion is welcome! No need to sit on the fence. > I'm fine with whatever option above is chosen, with the only caveat > being that if its in qemu.git, I don't think it belongs under contrib/ > it should be a top level dir of its own. > Dave > Regards, > Daniel > -- > |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| > |: https://libvirt.org -o- https://fstop138.berrange.com :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| -- Dr. David Alan Gilbert / [email protected] / Manchester, UK
